Longtime NBA player, occasional boxer and current Comcast SportsNet Bulls analyst Kendall Gill apparently crossed that line on Tuesday night. According to observers, Gill and Big Ten Network analyst Tim Doyle fought in the CSN newsroom. Gill, as you can see in the video above, called out the refs for "a very bad call," and Doyle took exception to that characterization on-air in a later show. Crain's Chicago Business Report columnist Danny Ecker has an eyewitness account of what happened next:

Mr. Gill approached Mr. Doyle and called him out for his comments, which escalated to a shoving match and ultimately Mr. Gill throwing a punch at Mr. Doyle. The two bumped up against a sign on the wall and a small amount of blood was drawn (though it was unclear exactly how) before the two were separated.

This, of course, is not the kind of behavior you want your on-air talent exhibiting (unless it's "First Take," that is), and as a result, CSN has suspended Gill.

"We're looking further into the incident that took place in our newsroom earlier today," said CSN Chicago news director Kevin Cross in a statement. "Until the investigation is complete, Kendall Gill will not be appearing on our air."

Gill played 15 seasons in the NBA for seven teams, including the Bulls. He's also a professional boxer with a record of 4-0 (including three knockouts), which may not help him in forming opinions, but surely helps in defending them.